School of Environmental Science and Engineering, Guangdong Provincial Key Laboratory of Soil and Groundwater Pollution Control, Southern University of Science and Technology, 1088 Xueyuan Blvd, Nanshan District, Shenzhen 518055, PR China; State Environmental Protection Key Laboratory of Integrated Surface Water-Groundwater Pollution Control, School of Environmental Science and Engineering, Southern University of Science and Technology, Shenzhen 518055, PR China; School of Environment, Harbin Institute of Technology, Harbin 150090, PR China.
School of Environmental Science and Engineering, Guangdong Provincial Key Laboratory of Soil and Groundwater Pollution Control, Southern University of Science and Technology, 1088 Xueyuan Blvd, Nanshan District, Shenzhen 518055, PR China; State Environmental Protection Key Laboratory of Integrated Surface Water-Groundwater Pollution Control, School of Environmental Science and Engineering, Southern University of Science and Technology, Shenzhen 518055, PR China.
Waste Manag. 2019 Nov;99:102-111. doi: 10.1016/j.wasman.2019.08.029. Epub 2019 Aug 30.
Heavy metals such as lead, zinc, and copper always coexist in industrial wastes and tend to be released if the wastes are not treated properly. With abundant contents of aluminum, iron and silicon, sewage sludge incineration ash can provide a ceramic matrix for potential heavy metal stabilization. By using ceramic sintering, this study explored the coimmobilization mechanisms of lead, zinc and copper, with detailed explications on phase transformation, metal distribution and the effect of metal content. PbAlSiO was identified as the major phase for lead immobilization in series with low heavy metal content, while most of the lead was incorporated into Pb(PO) in high metal series. The ZnCuFeAlO spinel solid solution was the predominant product phase for copper and zinc stabilization in both reaction series, but zinc was more competitively incorporated into the spinel structure. Moreover, the pattern of heavy metal distribution in the sintered products was largely affected by the metal type and elemental composition of the reaction system. Although different leaching behaviors were observed for the three heavy metals, their leachability was found to reach very low value after the thermal treatment processes. This study proposed a "waste-to-resource" strategy to largely alleviate the environmental burden of solid wastes and heavy metal pollution by using sewage sludge incineration ash as raw materials for low-temperature glass-ceramics, with a simultaneous effect on metal immobilization.
重金属如铅、锌和铜总是在工业废物中共存，如果废物处理不当，往往会释放出来。污水污泥焚烧灰含有丰富的铝、铁和硅，可为潜在重金属稳定化提供陶瓷基质。本研究通过陶瓷烧结，探讨了铅、锌和铜的共固定化机制，详细说明了相变、金属分布和金属含量的影响。在低重金属含量系列中，PbAlSiO 被确定为铅固定化的主要相，而大部分铅则被掺入到高金属系列的 Pb(PO)中。ZnCuFeAlO 尖晶石固溶体是两种反应系列中铜和锌稳定化的主要产物相，但锌更具竞争力地掺入到尖晶石结构中。此外，烧结产物中重金属分布模式在很大程度上受到反应体系中金属类型和元素组成的影响。尽管三种重金属的浸出行为不同，但发现它们的浸出率在热处理后达到非常低的值。本研究提出了一种“废物变资源”的策略，利用污水污泥焚烧灰作为低温玻璃陶瓷的原料，在固定金属的同时，也大大减轻了固体废物和重金属污染的环境负担。
